患者，男性。胃、十二指肠溃疡出血，经对症治疗后出血停止，大便隐血阳性，出血期间，患者

  Napoga  is a 12—year---old  girl in Ghana, Africa. It is hard for her family to get clean water . Every morning , she leaves home at half past five to get clean water for her family in a village far away . It takes her six hours to get enough clean water for daily cooking and drinking. She has no time to go to school or to play with her friends. Millions of people in the world are like Napoga . They can’t get enough clean water to keep healthy.

Earth Day is April 22. But on all other days, we must also remember it. The water we use is the most important natural resource(自然资源)on the earth.

Water covers 70 perent of the earth’s surface (表面). But most of that is sea water. We can’t use it for very many things.  Fresh water covers only one percent of the earth’s surface.

You probably feel lucky that your life isn’t as hard as Napoga’s . But that doesn’t mean you don’t have to worry about water. We all face serious water problems. One of them is water pollution. All kinds of things from cars, factories, farms and homes make our rivers , lakes , and oceans dirty. Polluted water is very bad for people to drink. And dirty water is bad for fish , too. Now, thirty-four percent of all kinds of fish are dying out.

How do cars and factories make our water dirty? First, they pollute the air. Then , when it rains, the rain water comes down and makes our drinking water dirty. Dirty rain, called acid rain(酸雨), is also bad for plants ,animals and buildings.

Scientists say that in 30 years, more than half of the people in the world won’t have enough clean water. We have to learn how to save more water for ourselves  and our children. Here is some advice for saving water:

● Turn off the water while you brush your teeth. You can save as much as 450liters(升)each month.

● Leaky taps （漏水的龙头）waste a lot of water. Fix them right away.

●You can easily cut your 10—minute showers in half---and you’ll be just as clean.

●When you wash dishes, don’t let the water run.

●Only wash clothes when you have a lot to wash. If your washing machine isn’t full , you are wasting water!

根据材料内容，选择最佳答案，并将其标号填入题前括号内。

小题1:Every morning Napoga went to get clean water _________.

A．before she went to school

B．after she finished school

C．without going to school

D．after she played with her friends小题2:On the earth, _______________.

sea water is  more widely used than fresh water

B.there is very little water for our living

C.there is 71 percent of fresh water

D.we don’t need to worry about water

小题3:Acid rain____________________________.

A．is only bad for living things.

B．can be produced in factories

C．doesn’t do harm to people , but it’s bad for plants, animals and buildings.

D．doesn’t just do harm to human beings but to animals, plants and buildings.小题4:Which of the following wastes water?

A．We need ten minutes if we want a clean shower.

B．We should put in enough clothes when we wash them in washing machines.

C．You can keep yourself clean by having a shower for five minutes.

D．Don’t let the water run when we brush our teeth and wash dishes.小题5:What’s the main idea of the passage?____________.

A．Something must be done to prevent water from being polluted.

B．Clean water means much to human beings and living things around us.

C．It’s time to take care of the water we use.

D．Water is the most important natural resource on the earth.

阅读材料，回答下列问题。

北大荒不再开垦荒地

　　黑龙江农垦总局作出决定，北大荒不再开垦荒地，将集中力量抢救保护好三江平原。近来，有人不顾国家三令五申，擅自闯入自然保护区进行小开荒，破坏湿地生态资源。黑龙江总局发文重申，对重要生态功能区要进行重点保护，严禁在区内开荒，已开垦的荒地要迅速还林、还草、还湿地。

（1）湿地对东北生态环境有哪些重要的作用？

（2）怎样实现东北地区农业的可持续发展？

（3）东北平原地区农业的发展方向是什么？

导致阴损及阳的理论根据是（）

A.阴阳互根

B.阴阳对立

C.阴阳互用

D.阴阳转化

E.阴阳制约

若能防腐层存在较多漏点，为了保证油气管道达到保护状态，应增大（）。

A.最小保护电位

B.最大保护电位

C.保护电流密度

D.自然腐蚀电位

蒸汽管道的在扫时，应将管道中的单向阀、疏水器、滤网、温度计及流量孔板等全部拆除，用双盘短管接通管路。( )